From 3bb9487dfc066e2b63d3b4b001bf24b6123734c8 Mon Sep 17 00:00:00 2001
From: hap <happppp@users.noreply.github.com>
Date: Sun, 18 Feb 2024 22:25:12 +0100
Subject: [PATCH] h8: appears to be better for performance without virtual
 calls for r/w functions

---
 src/devices/cpu/h8/h8.cpp      | 36 +++++++++++++++++++++++++-------
 src/devices/cpu/h8/h8.h        | 12 +++++------
 src/devices/cpu/h8/h8s2000.cpp | 38 ----------------------------------
 src/devices/cpu/h8/h8s2000.h   |  7 -------
 4 files changed, 34 insertions(+), 59 deletions(-)

diff --git a/src/devices/cpu/h8/h8.cpp b/src/devices/cpu/h8/h8.cpp
index 8e68c2a7b71..6b0c004e2f6 100644
--- a/src/devices/cpu/h8/h8.cpp
+++ b/src/devices/cpu/h8/h8.cpp
@@ -474,33 +474,51 @@ void h8_device::state_string_export(const device_state_entry &entry, std::string
 	}
 }
 
+// FIXME: one-state bus cycles are only provided for on-chip ROM & RAM in H8S/2000 and H8S/2600.
+// All other accesses take *at least* two states each, and additional wait states are often programmed for external memory!
+
 u16 h8_device::read16i(u32 adr)
 {
-	m_icount -= 2;
+	if(m_has_exr)
+		m_icount--;
+	else
+		m_icount -= 2;
 	return m_cache.read_word(adr & ~1);
 }
 
 u8 h8_device::read8(u32 adr)
 {
-	m_icount -= 2;
+	if(m_has_exr)
+		m_icount--;
+	else
+		m_icount -= 2;
 	return m_program.read_byte(adr);
 }
 
 void h8_device::write8(u32 adr, u8 data)
 {
-	m_icount -= 2;
+	if(m_has_exr)
+		m_icount--;
+	else
+		m_icount -= 2;
 	m_program.write_byte(adr, data);
 }
 
 u16 h8_device::read16(u32 adr)
 {
-	m_icount -= 2;
+	if(m_has_exr)
+		m_icount--;
+	else
+		m_icount -= 2;
 	return m_program.read_word(adr & ~1);
 }
 
 void h8_device::write16(u32 adr, u16 data)
 {
-	m_icount -= 2;
+	if(m_has_exr)
+		m_icount--;
+	else
+		m_icount -= 2;
 	m_program.write_word(adr & ~1, data);
 }
 
@@ -563,9 +581,11 @@ void h8_device::set_irq(int irq_vector, int irq_level, bool irq_nmi)
 
 void h8_device::internal(int cycles)
 {
-	// all internal operations take an even number of states (at least 2 each)
-	// this only applies to: H8/300, H8/300L, H8/300H (not H8S)
-	m_icount -= cycles + 1;
+	// on H8/300, H8/300L, H8/300H (not H8S), all internal operations take an even number of states (at least 2 each)
+	if(!m_has_exr)
+		m_icount -= cycles + 1;
+	else
+		m_icount -= cycles;
 }
 
 void h8_device::illegal()
diff --git a/src/devices/cpu/h8/h8.h b/src/devices/cpu/h8/h8.h
index ab59c2c2e7c..885ca100c80 100644
--- a/src/devices/cpu/h8/h8.h
+++ b/src/devices/cpu/h8/h8.h
@@ -191,12 +191,12 @@ protected:
 	virtual int trapa_setup();
 	virtual void irq_setup() = 0;
 
-	virtual u16 read16i(u32 adr);
-	virtual u8 read8(u32 adr);
-	virtual void write8(u32 adr, u8 data);
-	virtual u16 read16(u32 adr);
-	virtual void write16(u32 adr, u16 data);
-	virtual void internal(int cycles);
+	u16 read16i(u32 adr);
+	u8 read8(u32 adr);
+	void write8(u32 adr, u8 data);
+	u16 read16(u32 adr);
+	void write16(u32 adr, u16 data);
+	void internal(int cycles);
 	void prefetch_switch(u32 pc, u16 ir) { m_NPC = pc & 0xffffff; m_PC = pc+2; m_PIR = ir; }
 	void prefetch_done();
 	void prefetch_done_noirq();
diff --git a/src/devices/cpu/h8/h8s2000.cpp b/src/devices/cpu/h8/h8s2000.cpp
index 7d056a63835..b8e8f18e8c6 100644
--- a/src/devices/cpu/h8/h8s2000.cpp
+++ b/src/devices/cpu/h8/h8s2000.cpp
@@ -15,42 +15,4 @@ std::unique_ptr<util::disasm_interface> h8s2000_device::create_disassembler()
 	return std::make_unique<h8s2000_disassembler>();
 }
 
-// FIXME: one-state bus cycles are only provided for on-chip ROM & RAM in H8S/2000 and H8S/2600.
-// All other accesses take *at least* two states each, and additional wait states are often programmed for external memory!
-
-u16 h8s2000_device::read16i(u32 adr)
-{
-	m_icount--;
-	return m_cache.read_word(adr & ~1);
-}
-
-u8 h8s2000_device::read8(u32 adr)
-{
-	m_icount--;
-	return m_program.read_byte(adr);
-}
-
-void h8s2000_device::write8(u32 adr, u8 data)
-{
-	m_icount--;
-	m_program.write_byte(adr, data);
-}
-
-u16 h8s2000_device::read16(u32 adr)
-{
-	m_icount--;
-	return m_program.read_word(adr & ~1);
-}
-
-void h8s2000_device::write16(u32 adr, u16 data)
-{
-	m_icount--;
-	m_program.write_word(adr & ~1, data);
-}
-
-void h8s2000_device::internal(int cycles)
-{
-	m_icount -= cycles;
-}
-
 #include "cpu/h8/h8s2000.hxx"
diff --git a/src/devices/cpu/h8/h8s2000.h b/src/devices/cpu/h8/h8s2000.h
index 3d1274fb726..2acf28abcd3 100644
--- a/src/devices/cpu/h8/h8s2000.h
+++ b/src/devices/cpu/h8/h8s2000.h
@@ -29,13 +29,6 @@ protected:
 
 	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
 
-	virtual u16 read16i(u32 adr) override;
-	virtual u8 read8(u32 adr) override;
-	virtual void write8(u32 adr, u8 data) override;
-	virtual u16 read16(u32 adr) override;
-	virtual void write16(u32 adr, u16 data) override;
-	virtual void internal(int cycles) override;
-
 	virtual void do_exec_full() override;
 	virtual void do_exec_partial() override;